Planning Solar Panels

evy wrote:

westend wrote:
One issue you're going to have with mounting any module on your roof is the carrier you have on there and shading. Even with nothing on the roof rack, if the modules are below the rack, a shade line will be crossing the cells and that shade line is going to be a thief of your harvest.
I'd suggest to do your audit and see how many amp hours/day you'll need. I'm thinking one large module will be enough to charge back fully in a morning.

If you look at my first post, and look at my roof rack, it is not your common "U" shape design that the side railings would be sticking up and casting shadows, it's basically an inverted "U"
The top platform has no sides.
And the flooring is made of a wire mesh that you can walk on so no shadows except maybe at sunrise/sunset if I have a kayak/canoe on the other side.

But yes I will do the audit.

As long as the modules are above the rack, no harm, no foul. If they are lower than the top of the rail of the rack, a shadow line will march across the modules with the transit of the Sun, ala a sundial. This will limit the harvest. If you camp in Ecuador, not much of a problem. If you are harvesting North of 45th parallel, you will see the effect, especially in Winter. Pull the truck into the sun and see if there are shadows. Raise modules accordingly.

I still believe there is good advantage to your initial installation plan, a module on the side with supports that elevate it. This leaves the roof rack to be used for it's purpose and no heroic measures to mount panels on the existing mesh. Tie wrapping acetate backed thin-flex modules sounds like a recipe for disaster. I think you'll also find that they do not produce power like a rigid module.

There are available panel racking systems or unistrut with attachment connections to various shapes. The racking systems have clips that allow modules to be attached easily. If you are contemplating full use of your roof rack, that is an another avenue to explore.

FWIW, when I was researching solar for my modest needs, it became evident that a single 24V (nominal) module and a small MPPT controller was going to give me good bang-for-the-buck, ease of installation, and give me good functionality from the controller. You can do your own cost analysis but be forewarned that with charge controllers, you get what you pay for. My controller was $200 but has temp compensation and full programmability for output and duration of cycles.